CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation of the
device at these or any other conditions above those indicated in the operational sections of this specification is not implied.
NOTE:
1.
θ
JA
is measured with the component mounted on a high effective thermal conductivity test board in free air. See Tech Brief TB379 for details.
Electrical Specifications
Test Conditions: V
CC
= 4.5V to 5.5V; Unless Otherwise Specified. Typicals are at V
CC
= 5V, T
A
= 25
o
C,
Note 2
SYMBOL
TEST CONDITIONS
TEMP
(
o
C)
MIN
TYP
MAX
UNITS
PARAMETER
DC CHARACTERISTICS
Driver Differential V
OUT
(no load)
Driver Differential V
OUT
(with load)
V
OD1
V
OD2
R = 50Ω (RS-422) (Figure 1A)
R = 27Ω (RS-485) (Figure 1A)
R
D
= 60Ω, -7V
≤
V
CM
≤
12V (Figure 1B)
Full
Full
Full
Full
Full
-
2.5
2
1.5
-
-
3
2.5
-
0.01
V
CC
-
5
-
0.2
V
V
V
V
V
Change in Magnitude of Driver
Differential V
OUT
for
Complementary Output States
Driver Common-Mode V
OUT
Change in Magnitude of Driver
Common-Mode V
OUT
for
Complementary Output States
Logic Input High Voltage
Logic Input Low Voltage
Logic Input Current
Input Current (A/Y, B/Z) (Note 5)
∆V
OD
R = 27Ω or 50Ω (Figure 1A)
V
OC
∆V
OC
R = 27Ω or 50Ω (Figure 1A)
R = 27Ω or 50Ω (Figure 1A)
Full
Full
-
-
-
0.01
3
0.2
V
V
V
IH
V
IL
I
IN1
I
IN2
DE, DI, RE
DE, DI, RE
DE, DI, RE
DE = 0V, V
CC
= 0V or
4.5 to 5.5V
-7V
≤
V
CM
≤
12V
V
CM
= 0V
I
O
= -4mA, V
ID
= 200mV
I
O
= -4mA, V
ID
= 200mV
0.4V
≤
V
O
≤
2.4V
-7V
≤
V
CM
≤
12V
DI, RE = 0V or V
CC
DE = V
CC
DE = 0V
V
IN
= 12V
V
IN
= -7V
Full
Full
Full
Full
Full
Full
25
Full
Full
Full
Full
Full
Full
Full
2
-
-1
-
-0.8
-0.2
-
4
-
-
12
-
-
60
-
-
-
-
-
-
40
-
-
-
-
1
0.8
-
-
0.8
1
1
-
0.2
-
-
0.4
±1
-
2.2
1
250
V
V
µA
mA
mA
V
mV
V
V
µA
kΩ
mA
mA
mA
Receiver Differential Threshold
Voltage
Receiver Input Hysteresis
Receiver Output High Voltage
Receiver Output Low Voltage
Three-State (high impedance)
Receiver Output Current
Receiver Input Resistance
No-Load Supply Current, Note 3
V
TH
∆V
TH
V
OH
V
OL
I
OZR
R
IN
I
CC
Driver Short-Circuit Current,
V
O
= High or Low
I
OSD1
DE = V
CC
, -7V
≤
V
Y
or V
Z
≤
12V (Note 4)
3
ISL81485
Electrical Specifications
Test Conditions: V
CC
= 4.5V to 5.5V; Unless Otherwise Specified. Typicals are at V
CC
= 5V, T
A
= 25
o
C,
Note 2
(Continued)
SYMBOL
I
OSR
TEST CONDITIONS
0V
≤
V
O
≤
V
CC
TEMP
(
o
C)
Full
MIN
7
TYP
-
MAX
85
UNITS
mA
PARAMETER
Receiver Short-Circuit Current
SWITCHING CHARACTERISTICS
Driver Input to Output Prop Delay
Driver Prop Delay Skew
Driver Differential Rise or Fall Time
Driver Enable to Output High
Driver Enable to Output Low
Matched Enable Switching
|t
AZH
- t
BZL
| or |t
BZH
- t
AZL
|
Driver Disable from Output High
Driver Disable from Output Low
Matched Disable Switching
|t
AHZ
- t
BLZ
| or |t
BHZ
- t
ALZ
|
Driver Maximum Data Rate
Receiver Input to Output Prop
Delay
Receiver Prop Delay Skew
| t
PLH
- t
PHL
|
Receiver Enable to Output High
Receiver Enable to Output Low
Receiver Disable from Output High
Receiver Disable from Output Low
Receiver Maximum Data Rate
NOTES:
t
PLH
, t
PHL
R
DIFF
= 54Ω, C
L
= 100pF (Figure 2)
t
SKEW
t
R
, t
F
t
ZH
t
ZL
∆t
EN
t
HZ
t
LZ
∆t
DIS
f
MAXD
R
DIFF
= 54Ω, C
L
= 100pF (Figure 2)
R
DIFF
= 54Ω, C
L
= 100pF (Figure 2)
C
L
= 50pF, SW = GND (Figure 3)
C
L
= 50pF, SW = V
CC
(Figure 3)
(Figure 3)
C
L
= 50pF, SW = GND (Figure 3)
C
L
= 50pF, SW = V
CC
(Figure 3)
(Figure 3)
|V
OD
|
≥
1.5V (Figure 4)
Full
Full
Full
Full
Full
Full
Full
Full
Full
Full
Full
Full
Full
Full
Full
Full
Full
2
-
-
-
-
-
-
-
-
30
8
-
-
-
-
-
30
9
1
5
9
9
1
9
9
2
-
17
1
7
7
7
7
-
15
5
15
25
25
3
25
25
5
-
30
5
20
20
20
20
-
ns
ns
ns
ns
ns
ns
ns
ns
ns
Mbps
ns
ns
ns
ns
ns
ns
Mbps
t
PLH
, t
PHL
(Figure 5)
t
SKD
t
ZH
t
ZL
t
HZ
t
LZ
f
MAXR
(Figure 5)
C
L
= 15pF, SW = GND (Figure 6)
C
L
= 15pF, SW = V
CC
(Figure 6)
C
L
= 15pF, SW = GND (Figure 6)
C
L
= 15pF, SW = V
CC
(Figure 6)
C
L
= 15pF, V
ID
≥
1.5V, RO t
H
and t
L
≥
20ns
2. All currents into device pins are positive; all currents out of device pins are negative. All voltages are referenced to device ground unless
otherwise specified.
3. Supply current specification is valid for loaded drivers when DE = 0V.
4. Applies to peak current. See “Typical Performance Curves” for more information.
5. Devices meeting these limits are denoted as “1 unit load (UL)” transceivers. The RS-485 standard allows up to 32 Unit Loads on the bus, so a
1UL transceiver permits > 32 devices on the bus.
Test Circuits and Waveforms
R
V
CC
DE
DI
D
Y
R
V
OC
Z
V
OD
V
CC
DE
DI
D
Y
Z
V
OD
R
D
= 60Ω
375Ω
V
CM
-7V to +12V
375Ω
FIGURE 1A. V
OD
AND V
OC
FIGURE 1B. V
OD
WITH COMMON MODE LOAD
FIGURE 1. DC DRIVER TEST CIRCUITS
4
ISL81485
Test Circuits and Waveforms
(Continued)
3V
DI
1.5V
1.5V
0V
t
PLH
C
L
= 100pF
Z
D
Y
SIGNAL
GENERATOR
R
DIFF
C
L
= 100pF
OUT (Z)
50%
50%
V
OL
t
PHL
t
PLH
V
OH
50%
t
PHL
V
OH
V
CC
DE
DI
OUT (Y)
50%
V
OL
DIFF OUT (Y - Z)
t
R
90%
10%
90%
10%
t
F
+V
OD
-V
OD
SKEW = |CROSSING PT. OF Y↑ & Z↓ - CROSSING PT. OF Y↓ & Z↑|
FIGURE 2A. TEST CIRCUIT
FIGURE 2B. MEASUREMENT POINTS
FIGURE 2. DRIVER PROPAGATION DELAY AND DIFFERENTIAL TRANSITION TIMES
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